Studies & Facts

So, just what do you know about Glycolic? Here are some facts to get you started.

  • Glycolic is one of the most studied ingredients used in cosmetic skin care and peel products to this day. An active Glycolic temporarily lowers the skin's pH. Depending on the strength in a finished consumer product, it usually stops working within 1 to 10 minutes. Toners and other such products can then be applied to restore the skin's pH.
  • Glycolic has known anti-inflammatory properties. However, it can be combined with other ingredients that might irritate the skin. The blend of combined ingredients that make up a formulation is commonly referred to as the ‘cosmetic matrix.’ Excessive ingredients in a 'cosmetic matrix' may either enhance or impact a product's overall effectiveness. For instance, added fragrance and coloring agents added to a 'cosmetic matrix' may be irritating to some skin types.
  • Active Glycolic has a tendency to tingle when first applied. This sensation generally subsides shortly after application and/or once the skin has become accustomed to the particular product.
  • Glycolic is most effective when in a gel or liquid based formulation. In over-the-counter skincare products, glycolic peels and micro-peels generally contain higher pH levels than those found in "professional use only" peels. However, glycolic is also known to be time, pH, and strength dependent; and may be rendered less active by pH adjusters. From a consumer's perspective, identifying the 'true' strength of a finished product can often pose a challenge. 



In a 2009 “Comparative Study on the Effect of Retinoic Acid, Glycolic Acid and Salicylic Acid on the Thin Skin,” Retinoic (0.05%), Glycolic (12%) and Salicylic (10%) acid preparations were applied, monitored and evaluated.

Regarding sensitive skin, and the conception that glycolic thins the skin, the Glycolic acid group showed several interesting results. While it decreased thickness of nucleated keratinocytes normally located on the outermost layer of the epidermis, it also increased thickness to the stratum spinosum and stratum granulosum, located in the bottom epidermal layers. In the end, a twofold increase in epidermal thickness was observed. Overall, a thicker epidermis is deemed better equipped to resist environmental damage.

Regarding wrinkles and skin firming, the Glycolic group showed a marked increase in collagen density and elastic fiber content. While both Retinoic and Glycolic acids-induced dermal fibroblastic stimulation to increase collagen and elastic fibers production, "Salicylic acid did not show dermal fibroblastic stimulation."

In acne, "Glycolic acid had anti- inflammatory effect.”

With pigmentation and skin lightening, “Glycolic acid induced degeneration in melanocytes with marked decrease of melanin.” In conclusion, both "Retinoic and Glycolic acids showed complementary actions in treatment of hyperpigmentation and as chemical peeling agents. Salicylic acid also is a peeling agent, but its effects could be covered by either Retinoic or Glycolic acids."

Reference: Comparative Study on the Effect of Retinoic Acid, Glycolic Acid and Salicylic Acid on the Thin Skin. Egypt. J. Histol. Vol. 32, No. 1, June, 2009: 17 – 32. (ISSN: 1110 - 0559). Original Article: Abeer A. Abd El Samad and Nagwa Kostandy Kalleny. Histology Department, Faculty of Medicine, Ain Shams University


For further reading on the subject of Glycolic, feel free to check out the following:

Glycolic Acid Peel Therapy – A Current Review

Chemical Peels: What's New and What Isn't New but Still Works Well

Glycolic Acid Peeling in the Treatment of Acne

Mode of Action of Glycolic Acid on Human Stratum Corneum: Ultrastructural and Functional Evaluation of the Epidermal Barrier